The United States expressed indignation at the conviction of American citizen, former US Marine Paul Whelan by a Russian court, VOA reported.

According to US Secretary of State Mike Pompeo, the US “outraged” by the court ruling after “a secret trial, with secret evidence, and without appropriate allowances for defense witnesses.”

“We have serious concerns that Mr. Whelan was deprived of the fair trial guarantees that Russia is required to provide him in accordance with its international human rights obligation,” Pompeo said in a statement.

The trial has been conducted behind closed doors amid national security concerns, with US Ambassador to Russia John Sullivan and other consular officials repeatedly denied access to hearings in recent months.